| 摘要 |
An object of the present invention is to provide a rolled material for high strength spring, which has excellent wire drawability even when suppressing the addition amount of an alloying element, and which can exhibit corrosion fatigue properties after quenching and tempering.;The present invention provides a rolled material for high strength spring, including C, Si, Mn, P, S, Al, Cu and Ni, wherein an amount of nondiffusible hydrogen is 0.40 ppm by mass or less, and an area ratio of ferrite expressed as a percentage satisfies an inequality expression (1) below, and a total area ratio of bainite and martensite is 2% or less:;Ferrite area ratio<{(0.77−[C])/0.77−[C]/3+0.08}×100 (1);where [name of element] in the above inequality expression (1) means a content expressed in % by mass of each element. |
